Liquid crystal displays (LCDs) have been widely applied to various electronic products. Since a display panel of the liquid crystal display is unable to emit light by itself, the liquid crystal display includes a backlight module for providing light to the display panel such that the display panel is able to display images. Generally, a conventional backlight module includes a back board, a light guide plate, a plurality of optical films, a frame and a light source. The light provided by the light source passes through the light guide plate and the optical films to evenly illuminate the display panel.
Generally, in order to fabricate elements of the backlight module, an edge of the back board has been subject to a prior punching process, so as to bend to a lateral wall or a barricade for fixing the optical films and the frame on the back board. However, with the trend of enlarging the screen size and thinning the thickness of an LCD, the structural strength at the edge of the conventional backlight module is usually insufficient, which results in the consequence that the LCD is easily deformed due to extruding or impact by external forces.